| Message ID | 20231228165707.3447-2-ilpo.jarvinen@linux.intel.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI: Solve two bridge window sizing issues | expand |
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index fd74f1c99dba..e3e6ff8854a7 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -820,11 +820,9 @@ static resource_size_t calculate_memsize(resource_size_t size, size = min_size; if (old_size == 1) old_size = 0; - if (size < old_size) - size = old_size; - size = ALIGN(max(size, add_size) + children_add_size, align); - return size; + size = max(size, add_size) + children_add_size; + return ALIGN(max(size, old_size), align); } resource_size_t __weak pcibios_window_alignment(struct pci_bus *bus,
pbus_size_mem() keeps the size of the optional resources in children_add_size. When calculating the PCI bridge window size, calculate_memsize() lower bounds size by old_size before adding children_add_size and performing the window size alignment. This results in double counting for the resources in children_add_size because old_size may be based on the previous size of the bridge window after it has already included children_add_size (that is, size1 in pbus_size_mem() from an earlier invocation of that function). As a result, on repeated remove of the bus & rescan cycles the resource size keeps increasing when children_add_size is non-zero as can be seen from this extract: iomem0: 23fffd00000-23fffdfffff : PCI Bus 0000:03 iomem1: 20000000000-200001fffff : PCI Bus 0000:03 iomem2: 20000000000-200002fffff : PCI Bus 0000:03 iomem3: 20000000000-200003fffff : PCI Bus 0000:03 iomem4: 20000000000-200004fffff : PCI Bus 0000:03 Solve the double counting by moving old_size check later in calculate_memsize() so that children_add_size is already accounted for. After the patch, the bridge window retains its size as expected: iomem0: 23fffd00000-23fffdfffff : PCI Bus 0000:03 iomem1: 20000000000-200000fffff : PCI Bus 0000:03 iomem2: 20000000000-200000fffff : PCI Bus 0000:03 Fixes: a4ac9fea016f ("PCI : Calculate right add_size") Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> --- drivers/pci/setup-bus.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)